xref: /original-bsd/lib/librpc/rpc/clnt_udp.c (revision e59fb703)
1 /* @(#)clnt_udp.c	2.2 88/08/01 4.0 RPCSRC */
2 /*
3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4  * unrestricted use provided that this legend is included on all tape
5  * media and as a part of the software program in whole or part.  Users
6  * may copy or modify Sun RPC without charge, but are not authorized
7  * to license or distribute it to anyone else except as part of a product or
8  * program developed by the user.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 #if !defined(lint) && defined(SCCSIDS)
31 static char sccsid[] = "@(#)clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro";
32 #endif
33 
34 /*
35  * clnt_udp.c, Implements a UDP/IP based, client side RPC.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  */
39 
40 #include <stdio.h>
41 #include <rpc/rpc.h>
42 #include <sys/socket.h>
43 #include <sys/ioctl.h>
44 #include <netdb.h>
45 #include <errno.h>
46 #include <rpc/pmap_clnt.h>
47 
48 extern int errno;
49 
50 /*
51  * UDP bases client side rpc operations
52  */
53 static enum clnt_stat	clntudp_call();
54 static void		clntudp_abort();
55 static void		clntudp_geterr();
56 static bool_t		clntudp_freeres();
57 static bool_t           clntudp_control();
58 static void		clntudp_destroy();
59 
60 static struct clnt_ops udp_ops = {
61 	clntudp_call,
62 	clntudp_abort,
63 	clntudp_geterr,
64 	clntudp_freeres,
65 	clntudp_destroy,
66 	clntudp_control
67 };
68 
69 /*
70  * Private data kept per client handle
71  */
72 struct cu_data {
73 	int		   cu_sock;
74 	bool_t		   cu_closeit;
75 	struct sockaddr_in cu_raddr;
76 	int		   cu_rlen;
77 	struct timeval	   cu_wait;
78 	struct timeval     cu_total;
79 	struct rpc_err	   cu_error;
80 	XDR		   cu_outxdrs;
81 	u_int		   cu_xdrpos;
82 	u_int		   cu_sendsz;
83 	char		   *cu_outbuf;
84 	u_int		   cu_recvsz;
85 	char		   cu_inbuf[1];
86 };
87 
88 /*
89  * Create a UDP based client handle.
90  * If *sockp<0, *sockp is set to a newly created UPD socket.
91  * If raddr->sin_port is 0 a binder on the remote machine
92  * is consulted for the correct port number.
93  * NB: It is the clients responsibility to close *sockp.
94  * NB: The rpch->cl_auth is initialized to null authentication.
95  *     Caller may wish to set this something more useful.
96  *
97  * wait is the amount of time used between retransmitting a call if
98  * no response has been heard;  retransmition occurs until the actual
99  * rpc call times out.
100  *
101  * sendsz and recvsz are the maximum allowable packet sizes that can be
102  * sent and received.
103  */
104 CLIENT *
105 clntudp_bufcreate(raddr, program, version, wait, sockp, sendsz, recvsz)
106 	struct sockaddr_in *raddr;
107 	u_long program;
108 	u_long version;
109 	struct timeval wait;
110 	register int *sockp;
111 	u_int sendsz;
112 	u_int recvsz;
113 {
114 	CLIENT *cl;
115 	register struct cu_data *cu;
116 	struct timeval now;
117 	struct rpc_msg call_msg;
118 
119 	cl = (CLIENT *)mem_alloc(sizeof(CLIENT));
120 	if (cl == NULL) {
121 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
122 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
123 		rpc_createerr.cf_error.re_errno = errno;
124 		goto fooy;
125 	}
126 	sendsz = ((sendsz + 3) / 4) * 4;
127 	recvsz = ((recvsz + 3) / 4) * 4;
128 	cu = (struct cu_data *)mem_alloc(sizeof(*cu) + sendsz + recvsz);
129 	if (cu == NULL) {
130 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
131 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
132 		rpc_createerr.cf_error.re_errno = errno;
133 		goto fooy;
134 	}
135 	cu->cu_outbuf = &cu->cu_inbuf[recvsz];
136 
137 	(void)gettimeofday(&now, (struct timezone *)0);
138 	if (raddr->sin_port == 0) {
139 		u_short port;
140 		if ((port =
141 		    pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
142 			goto fooy;
143 		}
144 		raddr->sin_port = htons(port);
145 	}
146 	cl->cl_ops = &udp_ops;
147 	cl->cl_private = (caddr_t)cu;
148 	cu->cu_raddr = *raddr;
149 	cu->cu_rlen = sizeof (cu->cu_raddr);
150 	cu->cu_wait = wait;
151 	cu->cu_total.tv_sec = -1;
152 	cu->cu_total.tv_usec = -1;
153 	cu->cu_sendsz = sendsz;
154 	cu->cu_recvsz = recvsz;
155 	call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
156 	call_msg.rm_direction = CALL;
157 	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
158 	call_msg.rm_call.cb_prog = program;
159 	call_msg.rm_call.cb_vers = version;
160 	xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
161 	    sendsz, XDR_ENCODE);
162 	if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
163 		goto fooy;
164 	}
165 	cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
166 	if (*sockp < 0) {
167 		int dontblock = 1;
168 
169 		*sockp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
170 		if (*sockp < 0) {
171 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
172 			rpc_createerr.cf_error.re_errno = errno;
173 			goto fooy;
174 		}
175 		/* attempt to bind to prov port */
176 		(void)bindresvport(*sockp, (struct sockaddr_in *)0);
177 		/* the sockets rpc controls are non-blocking */
178 		(void)ioctl(*sockp, FIONBIO, (char *) &dontblock);
179 		cu->cu_closeit = TRUE;
180 	} else {
181 		cu->cu_closeit = FALSE;
182 	}
183 	cu->cu_sock = *sockp;
184 	cl->cl_auth = authnone_create();
185 	return (cl);
186 fooy:
187 	if (cu)
188 		mem_free((caddr_t)cu, sizeof(*cu) + sendsz + recvsz);
189 	if (cl)
190 		mem_free((caddr_t)cl, sizeof(CLIENT));
191 	return ((CLIENT *)NULL);
192 }
193 
194 CLIENT *
195 clntudp_create(raddr, program, version, wait, sockp)
196 	struct sockaddr_in *raddr;
197 	u_long program;
198 	u_long version;
199 	struct timeval wait;
200 	register int *sockp;
201 {
202 
203 	return(clntudp_bufcreate(raddr, program, version, wait, sockp,
204 	    UDPMSGSIZE, UDPMSGSIZE));
205 }
206 
207 static enum clnt_stat
208 clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
209 	register CLIENT	*cl;		/* client handle */
210 	u_long		proc;		/* procedure number */
211 	xdrproc_t	xargs;		/* xdr routine for args */
212 	caddr_t		argsp;		/* pointer to args */
213 	xdrproc_t	xresults;	/* xdr routine for results */
214 	caddr_t		resultsp;	/* pointer to results */
215 	struct timeval	utimeout;	/* seconds to wait before giving up */
216 {
217 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
218 	register XDR *xdrs;
219 	register int outlen;
220 	register int inlen;
221 	int fromlen;
222 #ifdef FD_SETSIZE
223 	fd_set readfds;
224 	fd_set mask;
225 #else
226 	int readfds;
227 	register int mask;
228 #endif /* def FD_SETSIZE */
229 	struct sockaddr_in from;
230 	struct rpc_msg reply_msg;
231 	XDR reply_xdrs;
232 	struct timeval time_waited;
233 	bool_t ok;
234 	int nrefreshes = 2;	/* number of times to refresh cred */
235 	struct timeval timeout;
236 
237 	if (cu->cu_total.tv_usec == -1) {
238 		timeout = utimeout;     /* use supplied timeout */
239 	} else {
240 		timeout = cu->cu_total; /* use default timeout */
241 	}
242 
243 	time_waited.tv_sec = 0;
244 	time_waited.tv_usec = 0;
245 call_again:
246 	xdrs = &(cu->cu_outxdrs);
247 	xdrs->x_op = XDR_ENCODE;
248 	XDR_SETPOS(xdrs, cu->cu_xdrpos);
249 	/*
250 	 * the transaction is the first thing in the out buffer
251 	 */
252 	(*(u_short *)(cu->cu_outbuf))++;
253 	if ((! XDR_PUTLONG(xdrs, (long *)&proc)) ||
254 	    (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
255 	    (! (*xargs)(xdrs, argsp)))
256 		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
257 	outlen = (int)XDR_GETPOS(xdrs);
258 
259 send_again:
260 	if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
261 	    (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen)
262 	    != outlen) {
263 		cu->cu_error.re_errno = errno;
264 		return (cu->cu_error.re_status = RPC_CANTSEND);
265 	}
266 
267 	/*
268 	 * Hack to provide rpc-based message passing
269 	 */
270 	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
271 		return (cu->cu_error.re_status = RPC_TIMEDOUT);
272 	}
273 	/*
274 	 * sub-optimal code appears here because we have
275 	 * some clock time to spare while the packets are in flight.
276 	 * (We assume that this is actually only executed once.)
277 	 */
278 	reply_msg.acpted_rply.ar_verf = _null_auth;
279 	reply_msg.acpted_rply.ar_results.where = resultsp;
280 	reply_msg.acpted_rply.ar_results.proc = xresults;
281 #ifdef FD_SETSIZE
282 	FD_ZERO(&mask);
283 	FD_SET(cu->cu_sock, &mask);
284 #else
285 	mask = 1 << cu->cu_sock;
286 #endif /* def FD_SETSIZE */
287 	for (;;) {
288 		readfds = mask;
289 		switch (select(_rpc_dtablesize(), &readfds, (int *)NULL,
290 			       (int *)NULL, &(cu->cu_wait))) {
291 
292 		case 0:
293 			time_waited.tv_sec += cu->cu_wait.tv_sec;
294 			time_waited.tv_usec += cu->cu_wait.tv_usec;
295 			while (time_waited.tv_usec >= 1000000) {
296 				time_waited.tv_sec++;
297 				time_waited.tv_usec -= 1000000;
298 			}
299 			if ((time_waited.tv_sec < timeout.tv_sec) ||
300 				((time_waited.tv_sec == timeout.tv_sec) &&
301 				(time_waited.tv_usec < timeout.tv_usec)))
302 				goto send_again;
303 			return (cu->cu_error.re_status = RPC_TIMEDOUT);
304 
305 		/*
306 		 * buggy in other cases because time_waited is not being
307 		 * updated.
308 		 */
309 		case -1:
310 			if (errno == EINTR)
311 				continue;
312 			cu->cu_error.re_errno = errno;
313 			return (cu->cu_error.re_status = RPC_CANTRECV);
314 		}
315 		do {
316 			fromlen = sizeof(struct sockaddr);
317 			inlen = recvfrom(cu->cu_sock, cu->cu_inbuf,
318 				(int) cu->cu_recvsz, 0,
319 				(struct sockaddr *)&from, &fromlen);
320 		} while (inlen < 0 && errno == EINTR);
321 		if (inlen < 0) {
322 			if (errno == EWOULDBLOCK)
323 				continue;
324 			cu->cu_error.re_errno = errno;
325 			return (cu->cu_error.re_status = RPC_CANTRECV);
326 		}
327 		if (inlen < sizeof(u_long))
328 			continue;
329 		/* see if reply transaction id matches sent id */
330 		if (*((u_long *)(cu->cu_inbuf)) != *((u_long *)(cu->cu_outbuf)))
331 			continue;
332 		/* we now assume we have the proper reply */
333 		break;
334 	}
335 
336 	/*
337 	 * now decode and validate the response
338 	 */
339 	xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
340 	ok = xdr_replymsg(&reply_xdrs, &reply_msg);
341 	/* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
342 	if (ok) {
343 		_seterr_reply(&reply_msg, &(cu->cu_error));
344 		if (cu->cu_error.re_status == RPC_SUCCESS) {
345 			if (! AUTH_VALIDATE(cl->cl_auth,
346 				&reply_msg.acpted_rply.ar_verf)) {
347 				cu->cu_error.re_status = RPC_AUTHERROR;
348 				cu->cu_error.re_why = AUTH_INVALIDRESP;
349 			}
350 			if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
351 				xdrs->x_op = XDR_FREE;
352 				(void)xdr_opaque_auth(xdrs,
353 				    &(reply_msg.acpted_rply.ar_verf));
354 			}
355 		}  /* end successful completion */
356 		else {
357 			/* maybe our credentials need to be refreshed ... */
358 			if (nrefreshes > 0 && AUTH_REFRESH(cl->cl_auth)) {
359 				nrefreshes--;
360 				goto call_again;
361 			}
362 		}  /* end of unsuccessful completion */
363 	}  /* end of valid reply message */
364 	else {
365 		cu->cu_error.re_status = RPC_CANTDECODERES;
366 	}
367 	return (cu->cu_error.re_status);
368 }
369 
370 static void
371 clntudp_geterr(cl, errp)
372 	CLIENT *cl;
373 	struct rpc_err *errp;
374 {
375 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
376 
377 	*errp = cu->cu_error;
378 }
379 
380 
381 static bool_t
382 clntudp_freeres(cl, xdr_res, res_ptr)
383 	CLIENT *cl;
384 	xdrproc_t xdr_res;
385 	caddr_t res_ptr;
386 {
387 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
388 	register XDR *xdrs = &(cu->cu_outxdrs);
389 
390 	xdrs->x_op = XDR_FREE;
391 	return ((*xdr_res)(xdrs, res_ptr));
392 }
393 
394 static void
395 clntudp_abort(/*h*/)
396 	/*CLIENT *h;*/
397 {
398 }
399 
400 static bool_t
401 clntudp_control(cl, request, info)
402 	CLIENT *cl;
403 	int request;
404 	char *info;
405 {
406 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
407 
408 	switch (request) {
409 	case CLSET_TIMEOUT:
410 		cu->cu_total = *(struct timeval *)info;
411 		break;
412 	case CLGET_TIMEOUT:
413 		*(struct timeval *)info = cu->cu_total;
414 		break;
415 	case CLSET_RETRY_TIMEOUT:
416 		cu->cu_wait = *(struct timeval *)info;
417 		break;
418 	case CLGET_RETRY_TIMEOUT:
419 		*(struct timeval *)info = cu->cu_wait;
420 		break;
421 	case CLGET_SERVER_ADDR:
422 		*(struct sockaddr_in *)info = cu->cu_raddr;
423 		break;
424 	default:
425 		return (FALSE);
426 	}
427 	return (TRUE);
428 }
429 
430 static void
431 clntudp_destroy(cl)
432 	CLIENT *cl;
433 {
434 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
435 
436 	if (cu->cu_closeit) {
437 		(void)close(cu->cu_sock);
438 	}
439 	XDR_DESTROY(&(cu->cu_outxdrs));
440 	mem_free((caddr_t)cu, (sizeof(*cu) + cu->cu_sendsz + cu->cu_recvsz));
441 	mem_free((caddr_t)cl, sizeof(CLIENT));
442 }
443